I remember back in my high school, when we started electrolysis, I became quite interested in it. I decided to do a home experiment on electrolysis of water. I grabbed my graphite pencils, a glass of water made of steel, two wires and some water. I wrapped the wire on my graphite nibs(on one end) and immersed the other end in water. I connected the wires to 240V AC supply(that was the supply which powers our home.)
Initially, bubbles formed on both of the electrodes(I think they must be a hydrogen/oxygen mixture since the cathode and anode switches in between due to ac)
The glass of water became very hot with the passage of time(which was due to resistance heating i suppose)
The interesting part came when I added a few grams of table salt to water. Within seconds, the graphite rods turned red and there were fumes of gas(most probably it was steam cause the fumes were white.) There might have been sparks in the plug as well, but I don't remember for sure. I immediately pulled the plug out before it got any worse.
I didnt try anything of that sort again as i knew i could have done worse than that. But it doesnt cause any harm in knowing what actually happened when I added salt.
Why did the graphite turned glowing red?
What was the composition of those fumes?
What more could have gone worse?